Magneto



W. W. HAWKINS MAGNET) Filed Feb. 20, 1922 2 Sheets-Sheet 1 k? //9/g l ATTYS.

w. w. HAWKINS MAGNETO Filed Feb. 20, 1922 2 Sheets-Sheet 2 Patented Oct. 28, 1924.

UNITED STATES PATENT OFFICE.

WILLIAM W. HAWKINS, OF BROOKLYN, NEKV YORK, nSSI-GNOR- TO WEBSTER ELECTRIC COMPANY, OF RACINE, WISCONSIN, A GORIEOBATION OF WISCONSIN.

MAGNETO.

Application filed February 20, 1922. Serial No. 537,989.

1 0 all whom it may concern Be it known that 1, WILLIAM N.

HAwKrNs, a citizen of the United States,

and resident of Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Improvement in Magnetos, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this speciiication.

This invention relates to magnetos such as are used in ignition systems for internal combustion engines, and particularly to magnetos of the oscillator type.

The object of the present invention is the provision of a new and improved circuit arrangement for use with magnetos of this type, by means of which a spark of great intensity is obtained.

The feature of the invention is the provision of a transformer coil in association with the oscillator windings, and the ar-' rangement of the windings of the magneto and the controlling circuits therefor in such a manner that the flux flowing through the core of the transformer is caused to die down very rapidly.

In the drawings which illustrate one embodiment of my invention,

Figure l is a section through the magneto showing the magnet pole pieces, the coils thereon, and the rotor in substantially normal position;

Figure 2 is a view similar to Figure 1 but showing the rotor substantially in cocked or set position;

Figure 3 is a view similar to Figure l but showing the rotor slightly past normal position;

Figure 4 shows the rotor in substantially its extreme overthrow position;

Figure 5 is a view of the transformer coil and windings;

Figure 6 is a section of the transformer on the line 66 of Figure 5, and

Figure 7 is a circuit drawing schematically indicating the circuit connections of the various coils and parts connected in the circuit.

In magnetos of the type herein disclosed, there is mounted on the shaft an inductor comprising four right angularly extending arms. The shaft is provided with means associated with some moving part of the motor or engine by which the inductor is repeatedly moved to its set position against the tension of a spring or springs which, upon release of the shaft, operate to rapidly rotate the inductor back to and slightly be yond normal position, and then cause it to again return in a reverse direction to normal position.

Referring now to the drawings, in which like reference characters in the several figures represent corresponding parts, 11 indicates the usual U-shaped or horseshoe magnet, which is provided at its extremities with the three-legged or E-shaped pole pieces 12 and 13. About the central legs of each of the pole pieces 12 and 13 are the coils lat and 15, respectively.

Fixed to the rotor shaft 16 in any desired manner is the rotor including the right angularly extending arms l7, l8, l9 and 20. will be noted that the outer ends of the rotor arms 18 and 20 are of greater extent than are the ends of the arms 17 and 19. At 21 are indicated portions of the springs by means of which the rotor is returned to its normal position after being cooked by a moving part of the motor.

As the cooking and releasing means for the rotor, as well as the interrupter operating means, are well known in the art, they will not be shown or described in the present application.

As above set forth, the rotor is shown in substantially normal position in Figure 1, in its cocked position in Figure 2, slightly beyond cocked position in Figure 3, and in its extreme overthrow position in Figure 4.

In Figure 5, the core of a transformer is indicated at 22, about the opposite legs of which are wound the primary coil 23 and the secondary coil 24:.

The movable arm 25 of the interrupter is arranged to be operated at the desired time by means of the cam 26 driven from a moving part of the motor. The fixed contact of the interrupter is shown at 27.

Referring to Figure 7, it will be noted that the coils let and 15 wound about the middle legs of the pole pieces are in series with the coil 23, the condenser 28 and the interrupter contacts 25 and 27 being arranged in parallel with the coil 15 and also in parallel with each other. It should be noted, however, that the coils 1a and 15 are so wound on the magnet pole pieces that the current induced therein flows in opposite directions, as indicated by the arrows in Figure 7.

l-la-ving now described the arrangement of the several parts of the invention, the op eration will now be described.

When the magneto is at rest, the rotor willbe substantially in the position shown in Figure 1. When moved to cocked position, as shown in Figure 2', the magnetic lines or fiux will pass through the rotor arms 18 and 20, and through the middle legs of the magnet pole pieces about which are wound the coils 1e and 15.v The rotor shaft will now be released, and the inductor will be rapidly rotated in a clockwise direction by means of the springs 21. During this clockwise rotation, the magnetic lines or flux passing through the middle legs of the pole pieces will change very rapidly, thus tending to create a surge of current through the coils 14% and Due to the operation of the current induced in the coils 142 and 15, local magnetic currents will be set up which may extend substantially as indicated by the arrows in Figure '8. However, the inductor is caused to have sullicient overthrow so that the conducting path for these local currents isinterrupted, as indicated in Figure 4:, thus causing the flux through the middle legs of the ma net pole pieces to die down Very quickly.

The cam 26 for operating the movable contact of the interrupter is so arranged that contacts 25 and 27 will be in engage. ment during the return movement of the rotor shaft, but will be opened as the inductor approaches its extreme position.

As the coils M and 15 are so wound upon the legs of the pole pieces that the impulses crcated therein are in opposition, as i heated in 7, during the return movement of the inductor, the currents set up in both the coils will pass through the interrupter contacts 25 and 27. As the primary coil 23 is in series with the coil 14 and on the same side of the bridge including the interrupter contacts, the current set up in coil T/l will also pass through the coil 23, thus inducing flux or magnetic lines in the core lVhen the interrupter contacts 25 and are separated, the current flowing in the portion of the circuit including coil 15 operates to oppose the'current flowing in the portion of the circuit on the opposite side of the interrupter bridge. This opposing i of the current in coil 15 is augmented the discharge from the condenser 28.

Thus the current flowing through the priuiary coil 23 is not only caused to die down cry rapidly, but a reversal 0t current ough the coil will be brought about, thus z the flux in the core 22 to die down very quickly, creating a very high potential impulse in the secondary coil 24:.

While in the above description and in the drawings but a single embodiment of my invention is disclosed, it is to be understood that modifications therein are contemplated and the invention should be limited only by the scope of the appended claims.

Having thus described my invention, what I claim is:

1. In combination, a pair of magneto generating windings, a transformer comprising primary anc secondary windings, a closed circuit including said magneto generating windings and said primary, a conducting bridge across said circuit, said bridge in eluding interrupter contacts which, when closed, establish two current paths, one of which includes one of the generating windin s and said bridge, the other path including the other generating winding, the transformer primary and said bridge, means for creating currents in said generating windings which simultaneously traverse said conducting bridge in the same direction, and

means for opening said contacts, whereupon the current created in each generating winding tends to traverse the primary and the other generating winding, in opposition to the current created in such other generating winding.

2. A magneto comprising a. pair of generating windings, means for simultaneously generating currents in said windings, a transformer comprising primary and secondary windings, and means adapted first to include one of said generating windings in circuit with the primary of said transformer, and to short circuit the other generating winding, and then to include both of said generating windingsand said primary in a closed circuit, wherein each of said -gen erating windings tends to discharge its generated current through the transformer primary and through the other generating winding in opposition to the current created in saidother generating winding.

3. A. magneto generating winding having one end permanently grounded and its other end grounded through a connection which includes interruptercontacts, a transformer comprising primary and secondary windings, a second magneto generating winding having one end grounded through said interrupter contacts, and its other end connected with one end of the transformer primary, the other end of the primary being permanently grounded, means tor creating in said generating windings currents which simultaneously pass in the same direction through said contacts, and means for opening said contacts.

4;. In a magneto, a magnet, pole pieces therefor having legs, a pair of generating windings, one being wound about a leg of each of said pole pieces, a closed circuit including said windings, a bridge across said circuit, one end being joined to said circuit between said windings, means for rapidly changing the flux or magnetic lines through the said legs having said windings, said windings being so arranged on said legs that the currents therein are in opposition in said circuit, a transformer, a primary coil for said transformer in said circuit, and an interrupter in said bridge.

5. In a magneto, a magnet, pole pieces therefor having legs, a pair of generating windings, one being wound about a leg of each of said pole pieces, a closed circuit including said windings, a bridge across said circuit, one end being oined to said circuit between said windings, means for rapidly changing the flux or magnetic lines through the said legs having said windings, said windings being so arranged on said legs that the currents therein are in opposition in said circuit, a transformer, 21. primary coil for said transformer in said circuit, an interrupter in said bridge, and a condenser in parallel with said interrupter.

In witness whereof, I hereunto subscribe my name this 30th day of January, 1922. WILLIAM W. HAWKINS. Witnesses;

EDNA V. GUSTAFSON, EMILE BOURGEOIS. 

